1. Field of the Invention
The present invention relates to a music reproducing apparatus and a music reproducing method suitable for use in a car telephone or portable telephone.
2. Related Art
In portable telephone systems such as PDC (Personal Digital Cellular Telecommunication System) known as analog or digital cellular systems, or PHS (Personal Handy-Phone Systems), a telephone terminal device rings to alert a user at the time of arrival of a call. Conventionally, the alert was made by beeping sound, but it has recently replaced by a melody because the beeping sound is a kind of noise offensive to the ear.
The above-mentioned type of conventional telephone terminal device can generate a melody, but the melody is far from satisfactory quality.
To solve this problem, the use of a music piece reproducing apparatus with an automatic performance function has been considered effective. Such a conventional music piece reproducing apparatus capable of automatic performance includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM) and a tone generator. It reproduces a piece of music as follows: The CPU executes an automatic performance program stored in the ROM to read music data from the ROM or RAM while setting tone generation parameters on the tone generator.
Such a telephone terminal device is required to be compact, low priced and multi-functional. The built-in CPU must execute various kinds of operations such as to process incoming and outgoing calls and make a display. In other words, if the music piece reproducing apparatus is used in a portable type of the telephone terminal device, the CPU must carry out reproduction of a music piece in addition to other telephony functions, and this requires a high-speed CPU. The higher the processing speed of the CPU, the more the telephone terminal device costs.
The use of a melody IC with a melody reproducing function is also known. The melody IC is constituted of a tone generator, a sequencer, a ROM for storing musical score data, and another ROM for storing timbre data. Upon receipt of a music reproduction instruction from the outside, the melody IC reproduces melody tones along musical score data read from the musical score data ROM with timbres read from the timbre data ROM. If such a melody IC is incorporated into a telephone terminal device, the CPU is not required to perform reproduction of a music piece, and this makes it possible to use an inexpensive, low-speed CPU.
The melody IC, however, has a small storage capacity for the timbre data ROM. The storage capacity of the timbre data ROM is so small that the number of parameters and kinds of timbre data are limited, and this makes it difficult to generate tones of high quality or a variety of tones.
Further, the melody IC has a small storage capacity for the musical score data ROM such that the number of storable music pieces and the length of a music piece to be reproduced are limited. The storage capacity of the musical score data ROM is so small that a large amount of music data needed for reproducing a music piece of high quality cannot be stored, thereby prohibiting all but some melodies of low quality from being reproduced.